"Without DNS and the DNS servers operated by Internet service providers, computer users would not be able to browse web sites, send e-mail, or connect to any Internet services."
That's half the truth.
You can do anything, but not via Domain Names.
http://www.google.com - Without DNS, it doesn't work.
http://188.8.131.52 - Without DNS, it works, and is the exact same thing.
Well, not if it's all VHosted, but dedicated Hosts work fine.